fix: remove unnecessary re-parsing when experiment is off

When using the old parser, parsing already happens during streaming.
The finalization step is only needed for the new AssistantMessageParser.
This ensures the code executes exactly as before when experiment is disabled.

Author: daniel-lxs

src/core/task/Task.ts

@@ -1705,10 +1705,8 @@ export class Task extends EventEmitter<TaskEvents> {
 			if (this.isAssistantMessageParserEnabled && this.assistantMessageParser) {
 				this.assistantMessageParser.finalizeContentBlocks()
 				this.assistantMessageContent = this.assistantMessageParser.getContentBlocks()
-			} else {
-				// When using old parser, parse the complete message
-				this.assistantMessageContent = parseAssistantMessage(assistantMessage)
 			}
+			// When using old parser, no finalization needed - parsing already happened during streaming
 
 			if (partialBlocks.length > 0) {
 				// If there is content to update then it will complete and